This invention relates to an outboard motor and more particularly to an improved tachometer arrangement for an outboard motor.
The desirability of providing an engine speed sensor for outboard motors is well known. Generally, the tachometer for an outboard motor is powered by the generating coil of the power plant which generating coil is employed for supplying power to various accessories of the watercraft. However, as the number of electrical accessories on the watercraft increase, the output of the generating coil also must be increased. However, the load can widely fluctuate and this requires the use of voltage regulators for regulating the voltage so as to provide more uniform loading. However, modern voltage regulators cause the wave form of the output voltage to become rather narrow and spiky when the load is small. As a result, it is necessary to provide a very sensitive tachometer. When the tachometer becomes sensitive, then its readings can be upset by external noise. Furthermore, it is frequently the practice to position the tachometer at a substantial distance from the actual engine. This gives rise to further noise problems and sensitivity difficulties.
It is, therefore, a principal object of this invention to provide an improved tachometer for an outboard motor.
It is a further object of this invention to provide a tachometer for an outboard motor that is powered externally of the generating coil and directly from the spark ignition circuit of the outboard motor so as to permit the use of lower cost and more reliable tachometers.